A hernia is an abnormal protrusion of a peritoneal-lined sac through the musculo-aponeuronic covering of the abdomen. The most common treatment for a hernia is surgery to repair the opening in the muscle wall. Operations for hernias are among the most common procedures performed today, with about 750,000 hernia repairs performed annually.
Surgery involves an abdominal incision, after which the protruding tissue is either removed or pushed back into the abdomen and the abdominal wall is repaired and strengthened. The abdominal wall can be strengthened by sewing surrounding muscle over it, or it can be strengthened with a special type of mesh. Unfortunately, there have been several reports of complications with some mesh products used in hernia repair.
In a study performed by Junge et al, “Elasticity of the anterior abdominal wall and impact for reparation of incisional hernias using mesh implants”, Hernia, 5:113-118 (2001), the elasticity of the abdominal wall was measured and compared to that of commercially available non-resorbable hernia mesh implants. It was assumed that the flexibility of the abdominal wall is restricted by extensive implantation of large mesh implants, the more so if the mesh implants are integrated into scar tissue. In addition, the non-physiological stretching capability of the mesh implants contrast with the highly elastic abdominal wall and can give rise to shearing forces, favoring increased local remodeling and thus recurrence at the margin. It was concluded that mesh implants used for repairing incisional hernia should have an elasticity of at least 25% in vertical stretching and 15% in the horizontal stretching when subjected to a tensile strength of 16 N/cm, in order to achieve almost physiological properties.
U.S. Pat. No. 8,016,841 to Magnusson et al. (assigned to Novus Scientific Pte. Ltd.) describes a mesh implant with an interlocking knitted structure and indicates that this mesh is useful for hernia repairs. The mesh contains two or more sets of fibers with different degradation times. This mesh allegedly gradually adjusts to match the conditions of the underlying tissue structures, such as the abdominal wall, through the degradation of the first type of fibers. This mesh maybe formed using any knitting technique, and is preferably knitted using a warp-knit procedure. However, this mesh implant is initially a rigid material that becomes more flexible as one layer resorbs. This rigidity can cause problems and issues identified in study performed by Junge et al mentioned above. The initial rigidity could also cause shearing and tearing, resulting in more scarring.
Therefore there is a need for improved materials and methods for repairing hernias.
Breast reconstruction is the rebuilding of a breast that has been removed due to cancer or other diseases. This procedure involves the use of implants or relocated flaps of the patients own tissue to create a natural looking breast and reformation of a natural looking areola and nipple. In some situations, reconstruction may be possible immediately following breast removal. But in individuals with medical problems, like high blood pressure, obesity, and/or diabetes, the surgery is typically delayed. Breast reconstruction usually takes multiple operations, which are spread out over weeks or months.
The skin sparing mastectomy enables the muscle to be detached inferiorly where the lower skin flap affords coverage to the implant. Although more natural expansion (compared to earlier surgical techniques, such as the total muscle coverage technique) is possible due to the release of the pectoralis muscle, pectoral muscle retraction and implant bottoming out is still a problem.
Suturing the inferior edge of the muscle to the fascia therefore becomes necessary. The suturing technique often results in disruption, as sutures cut through the tissues with tension. Acellular dermal matrices (ACDM) have been used to solve this problem. The ACDM provides reinforcement to the muscle and also provides supplemental tissue to the space between the released muscle and the inframmary fold. However, problems encountered with ACDM include, seroma, infection, disruption, patient concerns and costs.
TIGR mesh, a synthetic, absorbable, woven scaffold has recently been used in breast reconstruction as a replacement for ACDM. However, this mesh implant is initially a rigid and becomes more flexible as one layer resorbs. The initial rigidity can cause shearing and tearing, resulting in more scarring. Additionally, the initial rigidity of this material could cause post-operative discomfort for the patient.
Therefore there is a need for improved materials and methods for breast reconstruction.
It is an object of the present invention to provide a resorbable, biocompatible device for breast reconstruction.
It is further object of the present invention to provide a resorbable, biocompatible device for hernia repair.
It is still another object of the present invention to provide an improved method for breast reconstruction, particularly following a mastectomy.
It is yet a further object of the present invention the present invention to provide an improved method for hernia repair.